Outage Delay Indication and Exploitation

ABSTRACT

Embodiments described herein relate to a system and method for providing flexible receiver configuration in wireless communication systems, such as 802.11 WLAN systems. In one embodiment, a wireless device may transmit a first data frame including first configuration information specifying a first configuration of the receiver to notify a remote device that the wireless device intends to configure its receiver according to the first configuration. After receiving an acknowledgement frame confirming the first configuration information, the wireless device may configure the receiver according to the first configuration. In another embodiment, a wireless device may receive a first data frame including first configuration information and further including a request that the wireless device configure its receiver according to the first configuration. In response, the wireless device may configure the receiver according to the first configuration. In either case, the wireless device may receive subsequent communications according to the first configuration.

PRIORITY INFORMATION

This application is a continuation-in-part of U.S. patent application Ser. No. 14/794,011, entitled, “Receive Operation Mode Indication for Power Save,” filed Jul. 8, 2015, which claims priority to U.S. provisional patent application Ser. No. 62/023,690, entitled “Receive Operation Mode Indication for Power Save,” filed Jul. 11, 2014, both of which are hereby incorporated by reference in their entirety as though fully and completely set forth herein. This application also claims priority to U.S. provisional patent application Ser. No. 62/276,786, entitled “Receive Operation Mode Indication for Power Save,” filed Jan. 8, 2016, which is hereby incorporated by reference in its entirety as though fully and completely set forth herein.

TECHNICAL FIELD

The present application relates to wireless devices, and more particularly to providing improved power management in Wireless LAN systems.

DESCRIPTION OF THE RELATED ART

Wireless communication systems are rapidly growing in usage. Further, wireless communication technology has evolved from voice-only communications to also include the transmission of data, such as Internet and multimedia content. A popular short/intermediate range wireless communication standard is wireless local area network (WLAN). Most moderns WLANs are based on the IEEE 802.11 standard and are marketed under the Wi-Fi brand name. WLAN networks link one or more devices to a wireless access point, which in turn provides connectivity to the wider Internet.

In 802.11 systems, devices that wirelessly connect to each other are referred to as “stations” or STA for short. In an 802.11 infrastructure network, stations can be either wireless access points or clients. Access points (APs), also referred to as wireless routers, act as base stations for the wireless network. APs transmit and receive radio frequency signals for communication with wireless client devices. APs also typically couple to the Internet in a wired fashion. Wireless clients operating on an 802.11 network can be any of various devices such as laptops, tablet devices, smart phones, or fixed devices such as desktop computers.

Alternatively, or additionally, an 802.11 network may include a peer-to-peer network, such as an independent base service set (IBSS) network (sometimes called ad hoc mode). For example, in an IBSS network, two or more stations may communicate directly as peers, without any station operating as a base station or master. As another example, in a Wi-Fi Direct network, one peer station may operate as a group owner, in a manner similar to an AP, while other peer stations operate as clients. Wireless client/peer devices are referred to herein as stations, STA devices, or simply as “STA”. Wireless client/peer devices are also referred to herein as mobile devices.

Since in most instances the devices communicating on a WLAN are mobile, battery-operated devices, power management is an important consideration. The IEEE 802.11 standards define a spatial multiplexing (SM) power save feature to allow a STA to operate with only one active receive chain for a significant portion of time for the purpose of power conservation. However, that feature suffers from several drawbacks, including poor media access control (MAC) efficiency due to required control frames, and inflexibility in configuring a receiver.

Therefore, improvements are desired in wireless communication systems. In particular, it would be desirable to provide improvements with respect to reduced power consumption and/or reduced latency in WLAN systems.

SUMMARY

Embodiments described herein relate to a system and method for providing flexible receiver configuration in wireless communication systems, such as 802.11 WLAN systems.

A method is disclosed, in which a wireless communication device may operate a receiver of the wireless communication device according to a first configuration of the receiver. The wireless communication device may transmit configuration information specifying a second configuration of the receiver. The wireless communication device may also transmit outage delay information specifying a length of time during which the receiver will be unavailable while the wireless communication device configures the receiver according to the second configuration.

In some embodiments, the disclosed method may further include the wireless communication device receiving an acknowledgement frame confirming the configuration information, and, in response, configuring the receiver according to the second configuration, wherein the configuring the receiver is completed within a length of time equal to the specified length of time following the receiving the acknowledgment frame.

In some embodiments, the method may further include the wireless communication device determining the outage delay information based at least in part on the second configuration of the receiver. For example, the determining the outage delay information may be based on a difference between the first configuration and the second configuration.

In some embodiments, the configuration information and the outage delay information may be transmitted in a same frame. Alternatively, the outage delay information may be transmitted during an association process between the wireless communication device and a second wireless communication device.

In some embodiments, the transmitted configuration information may further include at least one of an indication of a channel width of the receiver and an indication of a number of active receive spatial streams of the receiver.

A wireless communication device is also disclosed. The wireless communication device may include a receiver configured to receive wireless communications from a second wireless communication device, a transmitter configured to transmit wireless communications to the second wireless communication device, and a processor communicatively coupled to the receiver and the transmitter. The processor may be configured to cause the wireless communication device to perform steps similar to those of any of the methods above.

This Summary is provided for purposes of summarizing some exemplary embodiments to provide a basic understanding of aspects of the subject matter described herein. Accordingly, the above-described features are merely examples and should not be construed to narrow the scope or spirit of the subject matter described herein in any way. Other features, aspects, and advantages of the subject matter described herein will become apparent from the following Detailed Description, Figures, and Claims.

BRIEF DESCRIPTION OF THE DRAWINGS

A better understanding of the present disclosure can be obtained when the following detailed description of the embodiments is considered in conjunction with the following drawings.

FIG. 1 illustrates an example WLAN communication system, according to some embodiments;

FIG. 2 illustrates an example simplified block diagram of a WLAN Access Point (AP), according to some embodiments;

FIG. 3 illustrates an example simplified block diagram of a mobile device, according to some embodiments;

FIG. 4A illustrates a timeline demonstrating use by a wireless device of configuration information for signaling a configuration of its own receiver, according to some scenarios;

FIG. 4B illustrates a timeline demonstrating use by a wireless device of configuration information for signaling a configuration of a receiver of a remote wireless device, according to some scenarios;

FIGS. 5A and 5B are flowchart diagrams illustrating exemplary methods for reconfiguring a receiver in a wireless device, according to some scenarios;

FIG. 6 illustrates a timeline demonstrating use by a wireless device of configuration information for instructing a configuration of a receiver of a remote device, according to some scenarios;

FIG. 7 is a flowchart diagram illustrating an exemplary method for reconfiguring a receiver in a wireless device, according to some scenarios;

FIG. 8 illustrates an example of a frame having a MAC header that includes an RX Operating Mode field, according to some scenarios;

FIG. 9A illustrates a signal flow diagram depicting an outage delay resulting from reconfiguration of a receiver, according to some embodiments;

FIG. 9B illustrates a signal flow diagram depicting use by a wireless device of outage delay information in conjunction with configuration information;

FIG. 9C illustrates a signal flow diagram depicting use by a wireless device of outage delay information to achieve a power savings opportunity.

While the embodiments described in this disclosure may be susceptible to various modifications and alternative forms, specific embodiments thereof are shown by way of example in the drawings and are herein described in detail. It should be understood, however, that the drawings and detailed description thereto are not intended to limit the embodiments to the particular form disclosed, but on the contrary, the intention is to cover all modifications, equivalents and alternatives falling within the spirit and scope of the appended claims.

DETAILED DESCRIPTION OF THE EMBODIMENTS Acronyms

The following acronyms are used in the present disclosure.

AP: Access Point

A-PPDU: Aggregated PPDU

CW: Channel Width

IBSS: Independent Base Service Set

MAC: Media Access Control

NSS: Number of Spatial Streams

PLCP: Physical Layer Convergence Protocol

PPDU: PLCP Protocol Data Unit

PSDU: PLCP Service Data Unit

RAT: Radio Access Technology

RX: Receive

RXCW: Receive Channel Width

RXMR: Receive Mode Request

RXNSS: Receive Number of Spatial Streams

RXOM: Receive Operating Mode

SM: Spatial Multiplexing

STA: Station device, such as a client mobile device

TX: Transmit

WLAN: Wireless Local Area Network

TERMS

The following is a glossary of terms used in the present application:

Memory Medium—Any of various types of memory devices or storage devices. The term “memory medium” is intended to include an installation medium, e.g., a CD-ROM, floppy disks, or tape device; a computer system memory or random access memory such as DRAM, DDR RAM, SRAM, EDO RAM, Rambus RAM, etc.; a non-volatile memory such as a Flash, magnetic media, e.g., a hard drive, or optical storage; registers, or other similar types of memory elements, etc. The memory medium may include other types of memory as well or combinations thereof. In addition, the memory medium may be located in a first computer system in which the programs are executed, or may be located in a second different computer system which connects to the first computer system over a network, such as the Internet. In the latter instance, the second computer system may provide program instructions to the first computer for execution. The term “memory medium” may include two or more memory mediums which may reside in different locations, e.g., in different computer systems that are connected over a network. The memory medium may store program instructions (e.g., embodied as computer programs) that may be executed by one or more processors.

Carrier Medium—a memory medium as described above, as well as a physical transmission medium, such as a bus, network, and/or other physical transmission medium that conveys signals such as electrical, electromagnetic, or digital signals.

Computer System—any of various types of computing or processing systems, including a personal computer system (PC), mainframe computer system, workstation, network appliance, Internet appliance, personal digital assistant (PDA), personal communication device, smart phone, television system, grid computing system, or other device or combinations of devices. In general, the term “computer system” can be broadly defined to encompass any device (or combination of devices) having at least one processor that executes instructions from a memory medium.

Mobile Device—any of various types of computer systems devices which are mobile or portable and which performs wireless communications using WLAN communication. Examples of mobile devices include mobile telephones or smart phones (e.g., iPhone™, Android™-based phones), and tablet computers such as iPad, Samsung Galaxy, etc. Various other types of devices would fall into this category if they include both cellular and WiFi communication capabilities, such as laptop computers (e.g., MacBook), portable gaming devices (e.g., Nintendo DS™, PlayStation Portable™ Gameboy Advance™, iPhone™), portable Internet devices, and other handheld devices, as well as wearable devices such as wrist-watches, headphones, pendants, earpieces, etc. In general, the term “mobile device” can be broadly defined to encompass any electronic, computing, and/or telecommunications device (or combination of devices) which is easily transported by a user and capable of wireless communication using WLAN.

Wireless Device—any of various types of computer systems devices which performs wireless communications using WLAN communications. As used herein, the term “wireless device” may refer to a mobile device, as defined above, or to a stationary device, such as a wireless base station. For example a wireless device may be any type of wireless station of an 802.11 system, such as an access point (AP) or a client station (STA).

WLAN—The term “WLAN” has the full breadth of its ordinary meaning, and at least includes a wireless communication network or RAT that is serviced by WLAN access points and which provides connectivity through these access points to the Internet. Most modern WLANs are based on IEEE 802.11 standards and are marketed under the name “Wi-Fi”. A WLAN network is different from a cellular network.

Processing Element—refers to various elements or combinations of elements. Processing elements include, for example, circuits such as an ASIC (Application Specific Integrated Circuit), portions or circuits of individual processor cores, entire processor cores, individual processors, programmable hardware devices such as a field programmable gate array (FPGA), and/or larger portions of systems that include multiple processors.

Automatically—refers to an action or operation performed by a computer system (e.g., software executed by the computer system) or device (e.g., circuitry, programmable hardware elements, ASICs, etc.), without user input directly specifying or performing the action or operation. Thus the term “automatically” is in contrast to an operation being manually performed or specified by the user, where the user provides input to directly perform the operation. An automatic procedure may be initiated by input provided by the user, but the subsequent actions that are performed “automatically” are not specified by the user, i.e., are not performed “manually”, where the user specifies each action to perform. For example, a user filling out an electronic form by selecting each field and providing input specifying information (e.g., by typing information, selecting check boxes, radio selections, etc.) is filling out the form manually, even though the computer system must update the form in response to the user actions. The form may be automatically filled out by the computer system where the computer system (e.g., software executing on the computer system) analyzes the fields of the form and fills in the form without any user input specifying the answers to the fields. As indicated above, the user may invoke the automatic filling of the form, but is not involved in the actual filling of the form (e.g., the user is not manually specifying answers to fields but rather they are being automatically completed). The present specification provides various examples of operations being automatically performed in response to actions the user has taken.

FIG. 1—WLAN System

FIG. 1 illustrates an example WLAN system according to some embodiments. As shown, the exemplary WLAN system includes a mobile device 106 communicating over a wireless communication channel 142 with an Access Point (AP) 112. The AP 112 may communicate via a wired or wireless communication channel 150 with one or more other electronic devices (not shown) and/or another network 152, such as the Internet. Additional electronic devices, such as the remote device 154, may communicate with components of the WLAN system via the network 152. For example, the remote device 154 may be another mobile device.

The WLAN system may be configured to operate according to any of various communications standards, such as the various IEEE 802.11 standards. It should be understood that the WLAN system of FIG. 1 is only exemplary. Various embodiments disclosed herein may be applied to any of a variety of wireless communications network topologies, including peer-to-peer networks. For example, embodiments may be applied to independent base service set (IBSS) networks, mesh networks, Wi-Fi Direct networks, or Wi-Fi Aware networks.

FIG. 2—Access Point Block Diagram

FIG. 2 illustrates an exemplary block diagram of an Access Point (AP) 112. It is noted that the block diagram of the AP of FIG. 2 is merely one example of a possible system. As shown, the AP 112 may include processor(s) 204 which may execute program instructions for the AP 112. The processor(s) 204 may also be coupled to memory management unit (MMU) 240, which may be configured to receive addresses from the processor(s) 204 and translate those addresses to locations in memory (e.g., memory 260 and read only memory (ROM) 250) or to other circuits or devices.

The AP 112 may include at least one network port 270. The network port 270 may be configured to couple to a wired network and provide a plurality of devices, such as mobile devices 106, access to the Internet. For example, the network port 270 (or an additional network port) may be configured to couple to a local network, such as a home network or an enterprise network. For example the network port 270 may be an Ethernet port. The local network may provide connectivity to additional networks, such as the Internet.

The AP 112 may include at least one antenna 234. The at least one antenna 234 may be configured to operate as a wireless transceiver and may be further configured to communicate with mobile device 106 via wireless communication circuitry 230, which may include, e.g., a radio. The antenna 234 communicates with the wireless communication circuitry 230 via communication chain 232. Communication chain 232 may include one or more receive chains, one or more transmit chains or both. The wireless communication circuitry 230 may be configured to communicate via Wi-Fi or WLAN, e.g., 802.11. The wireless communication circuitry 230 may be configured to communicate via various wireless communication technologies, including, but not limited to, LTE, LTE-A, GSM, WCDMA, CDMA2000, etc.

The AP 112 may be configured to implement part or all of the methods described herein, such as by reconfiguring a receiver included in the wireless communication circuitry 230 and/or the communication chain 232, or by requesting or accommodating reconfiguration of a receiver of a remote wireless device, such as the mobile device 106. For example, the processor(s) 204 of the AP 112 may be configured to implement part or all of the methods described herein, e.g., by executing program instructions stored on a memory medium (e.g., a non-transitory computer-readable memory medium). Alternatively, the processor 204 may be configured as a programmable hardware element, such as an FPGA (Field Programmable Gate Array), or as an ASIC (Application Specific Integrated Circuit), or a combination thereof.

FIG. 3—Mobile Device Block Diagram

FIG. 3 illustrates an example simplified block diagram of a mobile device 106. As shown, the mobile device 106 may include a system on chip (SOC) 300, which may include portions for various purposes. The SOC 300 may be coupled to various other circuits of the mobile device 106. For example, the mobile device 106 may include various types of memory (e.g., including NAND flash 310), a connector interface 320 (e.g., for coupling to a computer system, dock, charging station, etc.), the display 360, cellular communication circuitry 330 such as for LTE, GSM, etc., and short range wireless communication circuitry 329 (e.g., Bluetooth™ and WLAN circuitry). The mobile device 106 may further include one or more smart cards 310 that include SIM (Subscriber Identity Module) functionality, such as one or more UICC(s) (Universal Integrated Circuit Card(s)) cards 310. The cellular communication circuitry 330 may couple to one or more antennas, such as antennas 335 and 336 as shown. The short range wireless communication circuitry 329 may also couple to one or more antennas, such as antennas 337 and 338 as shown. Alternatively, the short range wireless communication circuitry 329 may couple to the antennas 335 and 336 in addition to, or instead of, coupling to the antennas 337 and 338. The short range wireless communication circuitry 329 may include multiple receive chains and/or multiple transmit chains for receiving and/or transmitting multiple spatial streams, such as in a multiple-input multiple output (MIMO) configuration.

As shown, the SOC 300 may include processor(s) 302 which may execute program instructions for the mobile device 106 and display circuitry 304 which may perform graphics processing and provide display signals to the display 360. The processor(s) 302 may also be coupled to memory management unit (MMU) 340, which may be configured to receive addresses from the processor(s) 302 and translate those addresses to locations in memory (e.g., memory 306, read only memory (ROM) 350, NAND flash memory 310) and/or to other circuits or devices, such as the display circuitry 304, cellular communication circuitry 330, short range wireless communication circuitry 329, connector interface (I/F) 320, and/or display 360. The MMU 340 may be configured to perform memory protection and page table translation or set up. In some embodiments, the MMU 340 may be included as a portion of the processor(s) 302.

As noted above, the mobile device 106 may be configured to communicate wirelessly using one or more radio access technologies (RATs). The mobile device 106 may be configured to communicate according to a WLAN RAT for communication in a WLAN network, such as that shown in FIG. 1. The mobile device 106 may also be configured to communicate on other RATs, such as cellular RATs, as desired.

The mobile device 106 may include hardware and software components for implementing all of the methods described herein, such as by reconfiguring a receiver, e.g., included in the short range wireless communication circuitry 329, or by requesting or accommodating reconfiguration of a receiver of a remote wireless device, such as the mobile device AP 112. For example, the processor 302 of the mobile device 106 may be configured to implement part or all of the features described herein, e.g., by executing program instructions stored on a memory medium (e.g., a non-transitory computer-readable memory medium). Alternatively (or in addition), the processor 302 may be configured as a programmable hardware element, such as an FPGA (Field Programmable Gate Array), or as an ASIC (Application Specific Integrated Circuit). Alternatively (or in addition) the processor 302 of the mobile device 106, in conjunction with one or more of the other components 300, 304, 306, 310, 320, 330, 335, 340, 350, 360 may be configured to implement part or all of the features described herein.

As used herein, the term “mobile device” may refer to a device such as the mobile device 106 described above.

FIGS. 4A-4B—Receiver-Initiated Receiver Configuration

A wireless device, such as the mobile device STA 106 or the access point AP 112, may configure its receiver to operate according to a plurality of configurations. For example, the wireless device may configure its receiver to operate with any of various channel widths. In some scenarios, the wireless device may select between channel widths of 20 MHz, 40 MHz, 80 MHz, or 160 MHz. As another example, the wireless device may configure its receiver to operate with any of various numbers of spatial streams. In some scenarios, the wireless device may select any integer number of spatial streams from 1 to 8. For example, this may be implemented by activating one receive chain for each of the selected number of spatial streams, while deactivating any remaining receive chains of the receiver. Thus, selecting a number of spatial streams may, in some cases, be synonymous with selecting a number of receive chains.

Selecting a smaller channel width and/or a lower number of spatial streams may allow a lower rate of power consumption by the receiver than selecting a larger channel width and/or a higher number of spatial streams. For example, selecting a lower number of spatial streams may allow hardware components of excess receive chains to be temporarily disabled. By contrast, selecting a larger channel width and/or a higher number of spatial streams may allow data to be transferred more quickly to the receiver than selecting a smaller channel width and/or a lower number of spatial streams.

In some embodiments the wireless device may use an estimate of expected traffic from a remote device, such as a STA 106 or AP 112, to determine a preferred configuration for the receiver of the wireless device. In some embodiments, the remote device may relay its transmission buffer size information (e.g., downlink queue size or uplink queue size) to the wireless device. This buffer size information may contain information such as the number of buffered octets, the access categories and/or traffic IDs of buffered traffic to be transmitted from the remote device to the wireless device. In some embodiments, the wireless device may use this buffer size information to determine preferred configuration parameters.

Additionally, in determining preferred configuration parameters, the wireless device may also, or alternatively, use information regarding costs associated with reconfiguring the receiver, such as time costs and/or power costs. For example, in some scenarios, the wireless device may determine that an amount of power required to reconfigure its receiver according to a smaller channel width and/or a lower number of spatial streams may exceed the power savings that may be expected as a result of operating at the smaller channel width and/or lower number of spatial streams while receiving the expected traffic. In response, the wireless device may determine not to reconfigure its receiver.

Similarly, during configuration of its receiver, the wireless device may be unable to receive transmissions. This downtime resulting from reconfiguration is referred to herein as “outage delay,” and represents a time cost resulting from reconfiguring the receiver. In some scenarios, the wireless device may determine that the outage delay resulting from reconfiguring the receiver according to a larger channel width and/or a higher number of spatial streams would exceed the time savings that may be expected as a result of operating at the larger channel width and/or higher number of spatial streams while receiving the expected traffic. In response, the wireless device may determine not to reconfigure its receiver. It may be preferable in some scenarios to select minimum configuration parameters sufficient to accommodate expected communication loads. Therefore, it may be advantageous to allow a wireless device to efficiently indicate to a remote device a preferred configuration of a receiver located either in the wireless device or in the remote device. For example, the preferred configuration may be based on information available to the wireless device regarding upcoming communication loads and/or costs associated with reconfiguration of the receiver.

FIGS. 4A and 4B illustrate timelines demonstrating use by a wireless device of configuration information for signaling a configuration of a receiver, according to two scenarios. Each of the FIGS. 4A and 4B demonstrates possible behavior of two wireless stations (STA₁ and STA₂), as time progresses from left to right. A current state of STA₁ is shown below each timeline. It should be appreciated that the timelines of FIGS. 4A and 4B include only details relevant to the explanation of the present embodiment, and may omit other details. For example, in some scenarios, STA₁ may transition at various times to other states, such as a Listen state, which are not illustrated in FIGS. 4A and 4B. It should also be appreciated that the various frames, delays, and other features illustrated in these and other figures may not be shown to scale, and are merely representative.

Although the two wireless stations are discussed herein as client stations, this is not intended to be limiting, and it should be understood that the illustrated timelines may instead involve communications between other wireless stations, such as between a client station and an AP, between a station and a group owner, or between peer stations, such as in IBSS mode. For example, the illustrated timelines may be implemented in an identical fashion with an AP in place of STA₁ and/or STA₂. For example, the illustrated procedures may be implemented by two devices including one or more of the mobile device 106 and the access point 112.

FIG. 4A illustrates a timeline demonstrating use by a wireless device (STA₁) of configuration information for signaling a configuration of its own receiver, according to some scenarios. As shown in FIG. 4A, STA₁ may transmit to STA₂ a data frame 402, while in a TX mode. The data frame 402 may include configuration information specifying a configuration according to which STA₁ intends to configure its receiver. For example, the configuration information may include an indication of a channel width and/or an indication of a number of spatial streams. In such an example, the configuration information may indicate that STA₁ intends to configure its receiver so as to receive signals having a channel width not greater than the indicated channel width and having a number of spatial streams not greater than the indicated number of spatial streams.

As illustrated in the example of FIG. 4A, the data frame 402 includes configuration information including an indication of a channel width of 40 MHz and an indication of a number of spatial streams of 2.

After transmitting the data frame 402, STA₁ may transition to an RX state. However, STA₁ may defer configuration of its receiver according to the transmitted configuration information until after it receives a confirmation that STA₂ has received the configuration information. Therefore, when STA₁ enters the RX state, its receiver may be configured according to a previously negotiated configuration. As illustrated in the example of FIG. 4A, the receiver of STA₁ is configured to receive signals having a channel width not greater than 80 MHz and having a number of spatial streams not greater than 3.

In response to receiving the data frame 402, STA₂ may transmit an acknowledgement frame 404, which may confirm receipt by STA₂ of the configuration information included in the data frame 402. For example, the acknowledgement frame 404 may include the same configuration information as the data frame 402, to confirm that STA₂ received the configuration information correctly. The acknowledgement frame 404 may be configured to accommodate the configuration of the receiver of STA₁, according to the previously negotiated configuration. For example, as illustrated in the example of FIG. 4A, the acknowledgement frame 404 may have a channel width not greater than 80 MHz and may have a number of spatial streams not greater than 3.

In response to receiving the acknowledgement frame 404, STA₁ may configure its receiver according to the configuration specified by the configuration information included in the data frame 402. As illustrated in the example of FIG. 4A, STA₁ configures its receiver to receive signals having a channel width not greater than 40 MHz and having a number of spatial streams not greater than 2. During this configuration of its receiver, STA₁ may be unable to receive transmissions. This downtime resulting from reconfiguration is referred to herein as “outage delay.” The length of the outage delay associated with a particular reconfiguration of a receiver may depend upon the changes to be made to the current configuration. According to some embodiments, changes to the number of spatial streams of the receiver may be performed quickly (e.g., within a few microseconds, such as within a Short Interframe Space (SIFS)), while changing the channel width of the receiver may take a longer time (e.g., a few milliseconds). FIG. 4A illustrates an outage delay following the acknowledgement frame 404. During the illustrated outage delay, STA₁ may configure its receiver according to the configuration information included in the data frame 402.

This configuration allows less communication traffic to be received in a fixed amount of time than the previous configuration. This transition may be performed, e.g., if STA₁ has information suggesting that RX traffic will be light, or if STA₁ has a need to conserve power. Thus, STA₁ may use information of which it is aware to efficiently configure its receiver in a configuration that may conserve power while still accommodating RX traffic.

While the receiver of STA₁ is configured according to the configuration specified by the configuration information included in the data frame 402, STA₂ may transmit to STA₁ a data frame 406. The data frame 406 may be configured to accommodate the configuration of the receiver of STA₁, as indicated by the configuration information included in the data frame 402. Specifically, the data frame 406 may have a channel width not greater than 40 MHz and may have a number of spatial streams not greater than 2. For example, the data frame 406 may have 2 spatial streams and a channel width of 40 MHz. As another example, the data frame 406 may have 1 spatial stream and a channel width of 20 MHz. More generally, any frames transmitted by STA₂ to STA₁ subsequent to the acknowledgement frame 404 may accommodate the configuration specified by the configuration information included in the data frame 402, until STA₁ and STA₂ negotiate a new configuration of the receiver of STA₁.

The data frame 406 may include configuration information specifying a configuration according to which STA₂ intends to configure its receiver. For example, the configuration information may have the same form as the configuration information included in the data frame 402. The configuration information included in the data frame 406 may be the same as or different than the configuration information included in the data frame 402. For example, STA₂ may intend to configure its receiver according to a different configuration than the receiver of STA₁. For example, STA₂ may expect to receive more communication from STA₁ than it expects to transmit to STA₁. As a specific example, STA₂ may be receiving a video stream from STA₁, and may therefore desire a channel width greater than 40 MHZ and/or a number of spatial streams greater than 2.

As illustrated in the example of FIG. 4A, the data frame 406 includes configuration information including an indication of a channel width of 160 MHz and an indication of a number of spatial streams of 8.

In response to receiving the data frame 406, STA₁ may transition to the TX state and transmit an acknowledgement frame 408. The acknowledgement frame 408 may confirm receipt by STA₁ of the configuration information included in the data frame 406. For example, the acknowledgement frame 408 may include the same configuration information as the data frame 406, to confirm that STA₁ received the configuration information correctly. The acknowledgement frame 408 may be configured to accommodate the configuration of the receiver of STA₂, according to a previously negotiated configuration.

In response to receiving the acknowledgement frame 408, STA₂ may configure its receiver according to the configuration specified by the configuration information included in the data frame 406. As illustrated in the example of FIG. 4A, STA₂ configures its receiver to receive signals having a channel width not greater than 160 MHz and having a number of spatial streams not greater than 8. Any frames transmitted by STA₁ to STA₂ subsequent to the acknowledgement frame 408 may accommodate the configuration specified by the configuration information included in the data frame 406, until STA₁ and STA₂ negotiate a new configuration of the receiver of STA₂.

FIG. 4B illustrates a timeline demonstrating use by a wireless device (STA₂) of configuration information for signaling a configuration of a receiver of a remote wireless device (STA₁), according to some scenarios. As shown in FIG. 4B, STA₁ may transmit to STA₂ a data frame 412, while in a TX mode. The data frame 412 may include configuration information specifying a configuration according to which STA₁ intends to configure its receiver. The data frame 412 may be similar to the data frame 402, as discussed above, and may include similar configuration information. As illustrated in the example of FIG. 4B, the data frame 412 includes configuration information including an indication of a channel width of 20 MHz and an indication of a number of spatial streams of 1.

After transmitting the data frame 412, STA₁ may transition to an RX state. However, STA₁ may defer configuration of its receiver according to the transmitted configuration information until after it receives a confirmation that STA₂ has received the configuration information. Therefore, when STA₁ enters the RX state, its receiver may be configured according to a previously negotiated configuration. As illustrated in the example of FIG. 4B, the receiver of STA₁ is configured to receive signals having a channel width not greater than 40 MHz and having a number of spatial streams not greater than 2.

In response to receiving the data frame 412, STA₂ may transmit an acknowledgement frame 414, which may confirm receipt by STA₂ of the configuration information included in the data frame 412. The acknowledgement frame 414 may be similar to the acknowledgement frame 404, as discussed above, and may include a similar confirmation of configuration information. The acknowledgement frame 414 may be configured to accommodate the configuration of the receiver of STA₁, according to the previously negotiated configuration. Specifically, the acknowledgement frame 414 may have a channel width not greater than 40 MHz and may have a number of spatial streams not greater than 2.

In response to receiving the acknowledgement frame 414, STA₁ may configure its receiver according to the configuration specified by the configuration information included in the data frame 412. As illustrated in the example of FIG. 4B, STA₁ configures its receiver to receive signals having a channel width not greater than 20 MHz and having a number of spatial streams not greater than 1. During this change in configuration, there may be an outage delay, during which STA₁ may be unable to receive transmissions, as illustrated in FIG. 4B.

While the receiver of STA₁ is configured according to the configuration specified by the configuration information included in the data frame 412, STA₂ may transmit to STA₁ a data frame 416. The data frame 416 may be configured to accommodate the configuration of the receiver of STA₁, as indicated by the configuration information included in the data frame 412. Specifically, the data frame 416 may have a channel width not greater than 20 MHz and may have a number of spatial streams not greater than 1. More generally, any frames transmitted by STA₂ to STA₁ subsequent to the acknowledgement frame 414 may accommodate the configuration specified by the configuration information included in the data frame 412, until STA₁ and STA₂ negotiate a new configuration of the receiver of STA₁.

The data frame 416 may include a request for STA₁ to configure its receiver according to a new configuration. The data frame 416 may further include configuration information specifying the new configuration. For example, the configuration information specifying the new configuration may be in place of configuration information specifying a configuration according to which STA₂ intends to configure its receiver, as discussed in connection with the data frame 406 of FIG. 4A. Specifically, in some scenarios, the configuration information specifying the new configuration may be in the same or similar form as the configuration information included in the data frame 402.

The request by STA₂ for STA₁ to configure its receiver according to the new configuration may be based, e.g., on information available to STA₂ indicating an expected increase in communication traffic. For example, STA₂ may be aware that it is about to transmit a large amount of communication traffic to STA₁. In some scenarios, STA₂ may request that STA₁ configure its receiver according to the new configuration in response to determining that the current configuration of the receiver of STA₁ is insufficient to accommodate the volume of communication traffic to be sent by STA₂.

As illustrated in the example of FIG. 4B, the data frame 416 includes configuration information including an indication of a channel width of 80 MHz and an indication of a number of spatial streams of 3.

In response to receiving the data frame 416, STA₁ may transition to the TX state and transmit an acknowledgement frame 418. The acknowledgement frame 418 may confirm the request and/or the configuration information included in the data frame 416. For example, the acknowledgement frame 418 may include the same configuration information as the data frame 416, to confirm that STA₁ received the configuration information correctly.

Alternatively, or in addition, the acknowledgement frame 418 may include an indicator of whether the configuration information included in the data frame 416 was accepted or denied, such as an acceptance bit. For example, the acknowledgement frame 418 may include an indication that STA₁ intends to reconfigure its receiver according to the configuration information included in the data frame 416. Alternatively, the acknowledgement frame 418 may include an indication that STA₁ does not intend to reconfigure its receiver according to the configuration information included in the data frame 416. In that case, the acknowledgement frame 418 may include other configuration information specifying another configuration according to which STA₁ does intend to configure its receiver. Such other configuration information may specify the current configuration of STA₁, or may specify a different configuration, such as a compromise configuration having parameters between those of the current configuration and those of the new configuration specified by the data frame 416. The acknowledgement frame 418 may be configured to accommodate the configuration of the receiver of STA₂, according to a previously negotiated configuration.

After transmitting the acknowledgement frame 418, STA₁ may transition to the RX state. In response to receiving the data frame 416, including the request and the configuration information, STA₁ may configure its receiver according to the new configuration specified by the configuration information. During this change in configuration, there may be an outage delay, during which STA₁ may be unable to receive transmissions, as illustrated in FIG. 4B. Alternatively, STA₁ may configure its receiver according to the configuration specified in the acknowledgement frame 418, which may match the new configuration specified by the data frame 416, or may include another configuration, as described above. As illustrated in the example of FIG. 4B, STA₁ configures its receiver to receive signals having a channel width not greater than 80 MHz and having a number of spatial streams not greater than 3, according to the new configuration specified by the data frame 416 and repeated by the acknowledgement frame 418.

In other scenarios, the acknowledge frame 418 may not indicate whether STA₁ intends to reconfigure its receiver according to the configuration information included in the data frame 416. Instead, STA₁ may transmit a subsequent data frame (not shown), similar to the data frame 412, that may include configuration information specifying a configuration according to which STA₁ intends to configure its receiver. If STA 1 accepts the configuration request included in the data frame 416, then the subsequent data frame may include configuration information mirroring the configuration information included in the data frame 416. Alternatively, the subsequent data frame may include other configuration information, such as the current configuration of STA₁, or a compromise configuration having parameters between those of the current configuration and those of the new configuration specified by the data frame 416.

While the receiver of STA₁ is configured according to the configuration specified by the configuration information included in the data frame 416 (or in the acknowledgement frame 418), STA₂ may transmit to STA₁ a data frame 420. The data frame 420 may be configured to accommodate the configuration of the receiver of STA₁, as indicated by the configuration information included in the data frame 416 (or in the acknowledgement frame 418). Specifically, the data frame 420 may have a channel width not greater than 80 MHz and may have a number of spatial streams not greater than 3. More generally, any frames transmitted by STA₂ to STA₁ subsequent to the acknowledgement frame 418 may accommodate the configuration specified by the configuration information included in the data frame 416 (or the acknowledgement frame 418), until STA₁ and STA₂ negotiate a new configuration of the receiver of STA₁.

The data frame 420 may include configuration information specifying a configuration according to which STA₂ intends to configure its receiver, as discussed in connection with the data frame 406 of FIG. 4A. In some scenarios, STA₂ may not intend to change the configuration of its receiver. In such scenarios, the configuration information included in the data frame 420 may specify a configuration identical to the current (e.g. most recently negotiated) configuration of the receiver of STA₂. As illustrated in the example of FIG. 4B, the data frame 420 includes configuration information including an indication of a channel width of 160 MHz and an indication of a number of spatial streams of 8.

In any scenario in which STA₁ denies the configuration information included in the data frame 416, STA₂ may repeat the request in one or more subsequent data frames. For example, the data frame 420 may include a request for STA₁ to configure its receiver according to a new configuration of a channel width of 80 MHz and an indication of a number of spatial streams of 3 (e.g., instead of the configuration information shown for the data frame 420 in FIG. 4B). In some scenarios, the number of times the request is repeated may communicate a degree of importance or urgency that STA₂ associates with having STA₁ accept the configuration information. For example, STA₁ may include logic for weighing any or all of the factors discussed above in deciding whether to transition to a new configuration, wherein a configuration requested by STA₂ is given an increased weight in response to each repeated request.

According to some scenarios, the configuration information discussed in connection with FIGS. 4A and 4B may be included within a frame header. For example, in the timeline of FIG. 4A, the configuration information included in the data frame 406 may be included within a frame header of the data frame 406. Additionally, the request for a remote wireless device to reconfigure its receiver may also be included within the frame header. For example, in the timeline of FIG. 4B, both the request and the configuration information included in the data frame 416 may be included within a frame header of the data frame 416.

As a specific example, the request and configuration information may be included within a MAC header, such as the MAC headers defined by the 802.11 standards.

According to some scenarios, the MAC header may include an RX Operating Mode (RXOM) field. For example, the RXOM field may be a 1-byte field. FIG. 8 illustrates one example of a frame having a MAC header including an RXOM field, according to some scenarios.

The RXOM field may include an RX Number of Spatial Streams (RXNSS) subfield indicating the maximum number of spatial streams to be received by the receiver. For example, the RXNSS subfield may be a 3-bit subfield indicating values 1-8.

The RXOM field may further include an RX Channel Width (RXCW) subfield indicating the channel width of the receiver. For example, the RXCW subfield may be a 3-bit subfield indicating a channel width of 20 MHz, 40 MHz, 80 MHz, or 160 MHz. If implemented as a subfield having 3 or more bits, the RXCW subfield may further be capable of indicating additional channel widths.

The RXOM field may further include an RX Mode Request (RXMR) subfield indicating to which receiver the RXOM field is directed. For example, the RXMR subfield may be a 1-bit subfield. In an exemplary scenario, if the RXMR subfield is set to 0, then the RXOM field may be directed to the receiver of the wireless device transmitting the RXOM field. I.e., if the RXMR subfield is set to 0, then the RXNSS subfield and the RXCW subfield may specify a configuration according to which the device transmitting the RXOM field intends to configure its receiver. If the RXMR subfield is set to 1, then the RXOM field may be directed to the receiver of the wireless device to which the frame containing the RXOM field is directed. I.e., if the RXMR subfield is set to 1, then the RXNSS subfield and the RXCW subfield may specify a configuration according to which the device receiving the RXOM field may configure its receiver. Specifically, the RXMR subfield set to 1 may act as a request for the receiving device to configure its receiver according to the configuration specified by the RXNSS subfield and the RXCW subfield.

The RXOM field may further include additional information, such as an outage time bit, as discussed below with regard to FIG. 9.

For example, the timelines of FIGS. 4A and 4B may be implemented using the RXOM field, as follows.

In the timeline of FIG. 4A, the data frame 402 may include a MAC header including the RXOM field, as defined above. Specifically, the configuration information included in the data frame 402 may include the RXOM field. The RXCW subfield may be set to a value indicating a channel width of 40 MHz. The RXNSS subfield may be set to a value indicating a number of spatial streams of 2. The RXMR subfield may be set to 0, indicating that the RXOM field is directed to the receiver of STA₁. I.e., the RXMR subfield set to 0 may indicate that the configuration information specifies a configuration according to which STA₁ intends to configure its receiver. The acknowledgement frame 404 may also include a MAC header including the RXOM field, which may be set to the same values as the RXOM field included in the data frame 402. The data frame 406 may include a MAC header including the RXOM field, in which the RXCW subfield may be set to a value indicating a channel width of 160 MHz, the RXNSS subfield may be set to a value indicating a number of spatial streams of 8, and the RXMR subfield may be set to 0. The acknowledgement frame 408 may also include a MAC header including the RXOM field, which may be set to the same values as the RXOM field included in the data frame 406.

Similarly, in the timeline of FIG. 4B, the data frame 412 may include a MAC header including the RXOM field, in which the RXCW subfield may be set to a value indicating a channel width of 20 MHz, the RXNSS subfield may be set to a value indicating a number of spatial streams of 1, and the RXMR subfield may be set to 0. The acknowledgement frame 414 may also include a MAC header including the RXOM field, which may be set to the same values as the RXOM field included in the data frame 412. The data frame 416 may include a MAC header including the RXOM field, in which the RXCW subfield may be set to a value indicating a channel width of 80 MHz, the RXNSS subfield may be set to a value indicating a number of spatial streams of 3, and the RXMR subfield may be set to 1. Specifically, the RXMR subfield set to 1 may include the request for STA₁ to configure its receiver according to the new configuration. The acknowledgement frame 418 may also include a MAC header including the RXOM field, which may be set to the same values as the RXOM field included in the data frame 412. Alternatively, the RXMR subfield included in the acknowledgement frame 418 may be set to 0.

FIGS. 5A-5B—Methods for Receiver-Initiated Receiver Configuration

FIGS. 5A and 5B are flowchart diagrams illustrating exemplary methods for reconfiguring a receiver in a wireless device, according to two scenarios. The methods shown in FIGS. 5A and 5B may be used in conjunction with any of the computer systems or devices shown in the above Figures, among other devices. If desired, it may be the case that each of the methods is more particularly implemented by a wireless device, or, more specifically, by a WLAN/Wi-Fi chipset within a wireless device. Implementing some embodiments of the method of either of FIGS. 5A and 5B may result in communications according to the timeline of either FIG. 4A or FIG. 4B. Some of the method elements shown may be performed concurrently or in a different order than shown, or may be omitted. Additional method elements may also be performed as desired. As shown, the methods may operate as follows.

As shown in FIG. 5A, at 502, a wireless device, such as the mobile device 106 or the AP 112, may transmit a first communication frame. The first communication frame may include first configuration information specifying a first configuration of a receiver in the wireless device. For example, the first configuration information may include at least one of an indication of a channel width of the receiver and an indication of a number of active receive spatial streams of the receiver. The first configuration information may be included in a header of the first communication frame. Specifically, the first configuration information may be included in a MAC header of the first communication frame.

According to some embodiments, an RX Operating Mode (RXOM) field, as defined in connection with the description of FIGS. 4A and 4B, may be included in the MAC header of the first communication frame. The RXOM field of the first communication frame may include the first configuration information. The first communication frame may further include an indication that the first configuration information includes a notice from the wireless device that the receiver will be configured according to the first configuration. For example, an RXMR subfield of the RXOM field may constitute the indication that the first configuration information includes a notice from the wireless device that the receiver will be configured according to the first configuration.

At 504, the wireless device may receive a first acknowledgement frame. The first acknowledgement frame may be configured according to a second configuration of the receiver. For example, the second configuration may be a current configuration of the receiver. The first acknowledgement frame may confirm the first configuration information. For example, the first acknowledgement frame may include the first configuration information, e.g., to confirm that it was received properly. The first configuration information may be confirmed in a header of the first acknowledgement frame. Specifically, the first configuration information may be confirmed in a MAC header of the first acknowledgement frame.

According to some embodiments, an RXOM field may be included in the MAC header of the first acknowledgement frame. The RXOM field of the first acknowledgement frame may confirm the first configuration information.

At 506, the wireless device may configure the receiver according to the first configuration. For example, the wireless device may configure the receiver to receive signals having a channel width not greater than the channel width indicated by the first configuration information, and having a number of spatial streams not greater than the number of spatial streams indicated by the first configuration information. The configuring the receiver may be in response to the receiving the first acknowledgement frame at 504.

At 508, the wireless device may receive a second communication frame after the configuring the receiver according to the first configuration at 506. The second communication frame may therefore be configured according to the first configuration. The second communication frame may include second configuration information specifying a third configuration of the receiver. The second configuration information may be included in a header of the second communication frame. Specifically, the second configuration information may be included in a MAC header of the second communication frame.

According to some embodiments, an RXOM field may be included in the MAC header of the second communication frame. The RXOM field of the second communication frame may include the second configuration information. The second communication frame may further include an indication that the second configuration information includes a request from a sender of the second communication frame that the receiver be configured according to the third configuration. For example, an RXMR subfield of the RXOM field may constitute the indication that the second configuration information includes a request from a sender of the second communication frame that the receiver be configured according to the third configuration.

At 510, the wireless device may transmit a second acknowledgement frame. The second acknowledgement frame may confirm the second configuration information. For example, the second acknowledgement frame may include the second configuration information, e.g., to confirm that it was received properly. The second configuration information may be confirmed in a header of the second acknowledgement frame. Specifically, the second configuration information may be confirmed in a MAC header of the second acknowledgement frame.

According to some embodiments, an RXOM field may be included in the MAC header of the second acknowledgement frame. The RXOM field of the second acknowledgement frame may confirm the second configuration information.

At 512, the wireless device may configure the receiver according to the third configuration. This may be in response to the receiving the second communication frame at 510.

At 514, the wireless device may receive a third communication frame after the configuring the receiver according to the third configuration at 512. The third communication frame may therefore be configured according to the third configuration.

As shown in FIG. 5B, at 522, a wireless device, such as the mobile device 106 or the AP 112, may receive a first communication frame. The first communication frame may include first configuration information specifying a first configuration of a receiver in a remote device. The remote device may also be a wireless device, such as the mobile device 106 or the AP 112. For example, the first configuration information may include at least one of an indication of a channel width of the receiver and an indication of a number of active receive spatial streams of the receiver. The first configuration information may be included in a header of the first communication frame. Specifically, the first configuration information may be included in a MAC header of the first communication frame.

According to some embodiments, an RXOM field, as defined in connection with the description of FIGS. 4A and 4B, may be included in the MAC header of the first communication frame. The RXOM field of the first communication frame may include the first configuration information. The first communication frame may further include an indication that the first configuration information includes a notice from the remote device that the receiver will be configured according to the first configuration. For example, an RXMR subfield of the RXOM field may constitute the indication that the first configuration information includes a notice from the remote device that the receiver will be configured according to the first configuration.

At 524, the wireless device may transmit a first acknowledgement frame. The first acknowledgement frame may be configured according to a second configuration of the receiver. Specifically, the first acknowledgement frame may be configured according to a format that is receivable by the remote device if the receiver of the remote device is configured according to the second configuration. For example, the second configuration may be a current configuration of the receiver. The first acknowledgement frame may confirm the first configuration information. For example, the first acknowledgement frame may include the first configuration information, e.g., to confirm that it was received properly. The first configuration information may be confirmed in a header of the first acknowledgement frame. Specifically, the first configuration information may be confirmed in a MAC header of the first acknowledgement frame.

According to some embodiments, an RXOM field may be included in the MAC header of the first acknowledgement frame. The RXOM field of the first acknowledgement frame may confirm the first configuration information.

At 528, the wireless device may transmit a second communication frame. The second communication frame may be configured according to the first configuration. Specifically, the second communication frame may be configured according to a format that is receivable by the remote device if the receiver of the remote device is configured according to the first configuration. The second communication frame may include second configuration information specifying a third configuration of the receiver. The second configuration information may be included in a header of the second communication frame. Specifically, the second configuration information may be included in a MAC header of the second communication frame.

According to some embodiments, an RXOM field may be included in the MAC header of the second communication frame. The RXOM field of the second communication frame may include the second configuration information. The second communication frame may further include an indication that the second configuration information includes a request from the wireless device that the receiver be configured according to the third configuration. For example, an RXMR subfield of the RXOM field may constitute the indication that the second configuration information includes a request from the wireless device that the receiver be configured according to the third configuration.

At 530, the wireless device may receive a second acknowledgement frame. The second acknowledgement frame may confirm the second configuration information. For example, the second acknowledgement frame may include the second configuration information, e.g., to confirm that it was received properly. The second configuration information may be confirmed in a header of the second acknowledgement frame. Specifically, the second configuration information may be confirmed in a MAC header of the second acknowledgement frame.

According to some embodiments, an RXOM field may be included in the MAC header of the second acknowledgement frame. The RXOM field of the second acknowledgement frame may confirm the second configuration information.

At 534, the wireless device may transmit a third communication frame. The third communication frame may be configured according to the third configuration. Specifically, the third communication frame may be configured according to a format that is receivable by the remote device if the receiver of the remote device is configured according to the third configuration.

FIG. 6—Transmitter-Initiated Receiver Configuration

FIG. 6 illustrates a timeline demonstrating use by a wireless device of configuration information for instructing a configuration of a receiver of a remote device, according to some scenarios. FIG. 6 demonstrates possible behavior of two wireless stations (STA₁ and STA₂), as time progresses from left to right. A current state of STA₁ is shown below the timeline. It should be appreciated that the timeline of FIG. 6 includes only details relevant to the explanation of the present embodiment, and may omit other details. For example, in some scenarios, STA₁ may transition at various times to other states, such as a Listen state, which are not illustrated in FIG. 6.

Although the two wireless stations are discussed herein as client stations, this is not intended to be limiting, and it should be understood that the illustrated timeline may instead involve communications between other wireless stations, such as between a client station and an AP. For example, the illustrated timeline may be implemented in an identical fashion with an AP in place of STA₁ and/or STA₂. For example, the illustrated procedures may be implemented by two devices including one or more of the mobile device 106 and the access point 112.

As shown in FIG. 6, STA₁ may transmit to STA₂ a mode request frame 602. The mode request frame 602 may indicate that STA₁ desires to enter a configuration control mode in which STA₂ may define a configuration of a receiver of STA₁. In some scenarios, the mode request frame 602 may include information regarding the capabilities of the receiver, such as a maximum channel width and/or maximum number of spatial streams that may be supported by the receiver. The mode request frame 602 may further include configuration information regarding an initial or current configuration of the receiver. For example, the configuration information may include an indication of a channel width and/or an indication of a number of spatial streams. In such an example, the configuration information may indicate that the receiver of STA₁ is configured so as to receive signals having a channel width not greater than the indicated channel width and having a number of spatial streams not greater than the indicated number of spatial streams.

In response to receiving the mode request frame 602, STA₂ may transmit a mode response frame 604. The mode response frame 604 may acknowledge that STA₂ is entering the configuration control mode. The mode response frame 604 may include configuration information regarding an initial configuration of the receiver, e.g. if such information was not provided by STA₁ in the mode request frame 602.

In other scenarios, the mode request frame 602 may be transmitted by STA₂ to STA₁, and the mode response frame 604 may be transmitted by STA₁ to STA₂. In either scenario, the timeline may proceed as illustrated following the transmission of the mode response frame 604.

After receiving the mode response frame 604, STA₁ may transition to an RX state with its receiver configured according to an initial configuration, e.g., as identified in the mode request message 602 or the mode response message 604. If the mode response message 604 includes configuration information regarding the initial configuration of the receiver, then STA₁ may configure its receiver according to the specified initial configuration. As illustrated in the example of FIG. 6, the receiver is initially configured to receive signals having a channel width not greater than 20 MHz and having a number of spatial streams not greater than 1. In some scenarios, this configuration may represent a configuration of minimum power consumption.

While STA₁ is configured according to the initial configuration, STA₂ may transmit an aggregated Physical Layer Convergence Protocol (PLCP) protocol data unit (PPDU). The aggregated PPDU (A-PPDU) may include a plurality of back-to-back physical layer (PHY) packets. Specifically, the A-PPDU may include a plurality of back-to-back PPDU packets, such as PPDU₁ and PPDU₂, as illustrated. Each PPDU packet may include a PLCP Service Data Unit (PSDU) and a PHY header. For example, PPDU₁ is illustrated as including a PHY header 606 and a PSDU 608. Similarly, PPDU₂ is illustrated as including a PHY header 610 and a PDSU 612.

PPDU₁ may be configured to accommodate the configuration of the receiver of STA₁ according to the initial configuration. Specifically, according to the example of FIG. 6, PPDU₁ may have a channel width not greater than 20 MHz and may have no more than 1 spatial stream.

However, STA₂ may prefer that the receiver of STA₁ be configured according to a different configuration. For example, STA₂ may prefer that the receiver of STA₁ be configured to accommodate a greater channel width and/or a larger number of spatial streams, e.g., if STA₂ has a large volume of data to transmit to STA₁. Thus, there may be a discrepancy between the current configuration of the receiver of STA₁ and a different configuration preferred by STA₂.

To resolve this discrepancy, the PHY header 606 of PPDU₁ may include configuration information specifying the different configuration. For example, while STA₁ and STA₂ are in the configuration control mode, the configuration information included in the PHY header 606 may constitute an instruction to STA₁ to configure its receiver according to the different configuration.

As illustrated in the example of FIG. 6, the PHY header 606 includes configuration information including an indication of a channel width of 80 MHz and an indication of a number of spatial streams of 3.

In response to receiving the PHY header 606, STA₁ may configure its receiver according to the different configuration. As illustrated in the example of FIG. 6, the receiver of STA₁ is configured to receive signals having a channel width not greater than 80 MHz and having a number of spatial streams not greater than 3.

However, STA₁ may not have sufficient time to configure its receiver before receiving the PSDU 608 of PPDU₁. Therefore, all of PPDU₁ may be configured to accommodate the configuration of the receiver of STA₁ according to the initial configuration (e.g., having only 1 spatial stream and a channel width not greater than 20 MHz). Thus STA₁ may have until the beginning of PPDU₂ to configure its receiver according to the different configuration specified by the PHY header 606.

PPDU₂ may be configured to accommodate the configuration of the receiver of STA₁ according to the different configuration specified by the PHY header 606. Specifically, according to the example of FIG. 6, PPDU₂ may have a channel width not greater than 80 MHz and may have no more than 3 spatial streams. Any subsequent PPDUs (not shown) included in the A-PPDU may similarly be configured to accommodate this configuration of the receiver of STA₁. Alternatively, the PHY header 610 or a subsequent PHY header (not shown) may include new configuration information specifying a new configuration of the receiver of STA₁. In response to receiving the new configuration information, STA₁ may configure its receiver according to the new configuration.

In response to receiving the A-PPDU, STA₁ may transmit an acknowledgement frame, such as a block acknowledge (BA) frame 614. The BA frame 614 may in some scenarios include an indication of whether the configuration information included in the PHY header 606 was accepted or denied, such as an acceptance bit. In other scenarios, the transmission of the BA frame 614 may inherently indicate that the configuration information was accepted. Following transmission of the BA frame 614, STA₁ may configure its receiver to resume the initial configuration. In scenarios where the initial configuration represents a configuration of minimum power consumption, resuming the initial configuration may serve to conserve power while the receiver is not actively receiving an A-PPDU. The BA frame 614 may include configuration information specifying the initial configuration, to notify STA₂ that STA₁ intends to configure its receiver according to the initial configuration. For example, the configuration information included in the BA frame 614 may be included in a PHY header of the BA frame 614.

According to some scenarios, the configuration information included in the PHY header 606 or other PHY headers may include an RXNSS subfield and an RXCW subfield, similar to those discussed above in connection with FIGS. 4A and 4B. For example, the RXNSS subfield may indicate the maximum number of spatial streams to be received by the receiver. For example, the RXNSS subfield may be a 3-bit subfield indicating values 1-8. The RXCW subfield may indicate the channel width of the receiver. For example, the RXCW subfield may be a 3-bit subfield indicating a channel width of 20 MHz, 40 MHz, 80 MHz, or 160 MHz. If implemented as a subfield having 3 or more bits, the RXCW subfield may further be capable of indicating additional channel widths.

It should be appreciated that, although the RXNSS and RXCW subfields included in the PHY header 606 may be structurally and/or functionally similar to the subfields discussed in connection with FIGS. 4A and 4B, they may be distinct subfields. For example, the RXNSS and RXCW subfields discussed in connection with FIG. 6 may be located in a PHY header, while the RXNSS and RXCW subfields discussed in connection with FIGS. 4A and 4B may be located in a MAC header, as discussed above.

Additionally, it should be appreciated that portions of the methods illustrated and discussed in connection with FIGS. 4A and 4B may be used in conjunction with the method illustrated and discussed in connection with FIG. 6. For example, in the example of FIG. 6, a MAC header included in the PSDU 608 may include configuration information specifying a configuration according to which STA₂ intends to configure its receiver, in a manner similar to that described in connection with the data frame 406 of FIG. 4A. In such a scenario, STA₁ may confirm the configuration information included in the PSDU 608, e.g., by including the configuration information in the BA 614, in a manner similar to that described in connection with the acknowledgement frame 408 of FIG. 4A.

FIG. 7—Method for Transmitter-Initiated Receiver Configuration

FIG. 7 is a flowchart diagram illustrating an exemplary method for reconfiguring a receiver in a wireless device, according to some scenarios. The method shown in FIG. 7 may be used in conjunction with any of the computer systems or devices shown in the above Figures, among other devices. If desired, it may be the case that the method is more particularly implemented by a wireless device, or, more specifically, by a WLAN/Wi-Fi chipset within a wireless device. Implementing some embodiments of the method of FIG. 7 may result in communications according to the timeline of FIG. 6. Some of the method elements shown may be performed concurrently or in a different order than shown, or may be omitted. Additional method elements may also be performed as desired. As shown, the method may operate as follows.

At 702, a wireless device, such as the mobile device 106 or the AP 112, may transmit a mode request frame. The mode request frame may include a request to initiate a configuration control mode. For example, the configuration control mode may allow a remote device (e.g., a remote wireless device, such as the mobile device 106 or the AP 112) to command the wireless device to configure a receiver of the wireless device according to a specified configuration.

At 704, the wireless device may receive a mode response frame. The mode response frame may confirm initiation of the configuration control mode. For example, the mode response frame may confirm that the remote device has entered the configuration control mode.

At 706, the wireless device may receive a first communication frame of a plurality of aggregated communication frames. The first communication frame may be configured according to a first configuration of the receiver. For example, the first configuration may be a current configuration of the receiver. The first communication frame may include first configuration information specifying a second configuration of the receiver. For example, the first configuration information may include at least one of an indication of a channel width of the receiver and an indication of a number of active receive spatial streams of the receiver. The first configuration information may be included in a header of the first communication frame. Specifically, the first configuration information may be included in a PHY header of the first communication frame. According to some embodiments, the first configuration information may include an RXCW subfield and an RXNSS subfield, as defined in connection with the description of FIG. 6.

At 708, the wireless device may configure the receiver according to the second configuration. For example, the wireless device may configure the receiver to receive signals having a channel width not greater than the channel width indicated by the first configuration information, and having a number of spatial streams not greater than the number of spatial streams indicated by the first configuration information. The configuring the receiver may be in response to the receiving the first communication frame at 706.

At 710, the wireless receiver may receive a second communication frame of the plurality of aggregated communication frames after the configuring the receiver according to the first configuration at 708. The second communication frame may therefore be configured according to the second configuration.

At 712, the wireless device may transmit an acknowledgement frame. The acknowledgement frame may include a block acknowledge (BA) frame. For example, the second acknowledgement frame may acknowledge receipt of the plurality of aggregated communication frames.

FIGS. 9A, 9B, and 9C—Outage Delay Signaling

In the preceding examples, configuration changes may result in outage delays, as illustrated in FIGS. 4A and 4B. FIGS. 9A-C further illustrates an outage delay.

Although FIGS. 9A, 9B, and 9C indicate a wireless station STA 106 and an access point AP 112, this is not intended to be limiting, and it should be understood that the illustrated interactions may instead involve communications between other wireless stations, such as between two client stations. For example, the illustrated interactions may occur in an identical fashion with another STA in place of AP 112.

FIG. 9A depicts a STA 106, in reference to FIG. 1, transitioning to a different bandwidth during communication with an AP 112, also in reference to FIG. 1. For example, the STA 106 may communicate a frame 906 to the AP 112, including configuration information specifying a configuration according to which the STA 106 intends to configure its receiver. The AP 112 may respond with an acknowledgement frame 908, which may confirm receipt by the AP 112 of the configuration information included in the frame 906. The STA 106 may configure its receiver according to the configuration specified by the configuration information included in the frame 906. During this transition, the STA 106 may be unable to receive or transmit to the AP 112. As noted previously, this downtime resulting from reconfiguration is referred to herein as “outage delay.” Thus, the AP 112 may suspend transmission to the STA 106 during the outage delay.

In some embodiments, the STA 106 may not indicate the duration of the outage delay at the time of configuration change. Instead, an AP 112 in such an embodiment may assume all outage delays from a STA 106 have the same duration. This assumed duration may be set by the STA 106 or the AP 112, e.g., during an association process between the STA 106 and the AP 112. Alternatively, the outage delay duration may be fixed by an industry standard, such as an IEEE 802.11 standard. In such embodiments, inefficiencies may exist, wherein an AP 112 suspends transmission to the STA 106 longer than the time necessary for the STA 106 to configure its receiver according to the configuration specified by the configuration information included in the frame 906.

To improve efficiency, the STA 106 may specify a duration of the outage delay describing the length of the outage delay in some units, such as microseconds. For example, a communication frame may include an Outage Delay field, e.g., in the MAC header or the PHY header. The Outage Delay field may, for example, consist of two octets defining a time value expressed in microseconds, which may therefore specify a maximum value of 65.535 ms. As another example, the Outage Delay field may consist of one octet defining a time value expressed in units of 20 microseconds, which may therefore specify a maximum value of 5.1 ms. In some embodiments, the STA 106 may specify a predetermined outage delay duration that is applied regardless of the receiver configuration information. In other embodiments, the STA 106 may specify a different outage delay duration dependent upon one or more factors, such as the current RXNSS/RXCW and/or the new RXNSS/RXCW indicated in a frame 906, to which the STA 106 is transitioning.

Additionally, an outage delay may not always occur following an RX Operating Mode change, as illustrated in FIG. 9B. For example, in some scenarios, a station may reconfigure its receiver according to a new configuration during an outage time 909. As used herein, an “outage time” is a period during which a station is aware that the AP will not be transmitting to the station. For example, during the outage time 909, a station may determine that its channel to the AP is busy (i.e., unavailable for communications by the wireless communication device). In response to this determination, the STA 106 may reconfigure its receiver (e.g., raising its RXNSS and/or RXCW) while the channel is busy. Then, once the channel is available for communication between the STA 106 and the AP 112, the station may transmit a frame 910 including configuration information specifying the configuration according to which the STA 106 has configured its receiver. Alternatively, during the outage time 909, the station may be in a power save mode (e.g., a doze state), and change its RXNSS and/or RXCW to larger or smaller values. Then, upon waking, the station may transmit the frame 910.

In scenarios in which the STA 106 reconfigures its receiver during an outage time, the STA 106 may indicate to the AP 112 that no outage delay will occur, to prevent the AP 112 from unnecessarily suspending transmission to the STA 106. For example, the STA 106 may include in the frame 910 an indication that no outage delay will occur. In some embodiments, the frame 910 may include an Outage Delay Indicator bit in the RXOM field. For example, if the Outage Delay Indicator bit is high, the station will not be available for the duration of the outage delay, whether or not a change will be made to the RXNSS or RXCW. If the outage delay indicator bit is set low, the station will not experience an outage delay, and the indicated values for RXNSS and RXCW may be used by the AP 112 immediately.

In response to receiving the frame 910, the AP 112 may transmit an acknowledge frame 916. Since the AP 112 is aware that no outage delay will occur following the acknowledge frame 916, the AP 112 can immediately send further communication frames following transmission of acknowledgement frame 916. Thus, the presence of an outage delay indication may allow for faster resumption of transmissions, as shown in FIG. 9B, as compared to FIG. 9A.

In some embodiments, an outage time may be due to an outage delay. Specifically, the STA 106 may be aware that the AP 112 will not be transmitting to the STA 106 during a known period because the STA 106 has informed the AP 112 of an outage delay during that period. Because of this, the STA 106 may use outage delay signaling to manufacture a power savings opportunity, as illustrated in FIG. 9C.

FIG. 9C illustrates a situation in which the presence of outage delay information may allow for a station to save power by creating an outage time having at least a known duration. In FIG. 9C, a STA 106 may initially be operating in a power save mode, during which it may not receive data. Upon exiting the power save mode, the STA 106 may notify the AP 112 that it is ready to receive data by transmitting a service initiation frame 912 to the AP 112. For example, the service initiation frame 912 may include a U-APSD trigger frame. In response to receiving the service initiation frame 912, the AP may send an acknowledge frame 918 to the station. After transmitting the acknowledge frame 918, the AP 112 may and move frames from a data buffer to the transmission buffer. In some cases, this movement of frames to the transmission buffer may result in an outage time 920, which may be of sufficient length to allow for the STA 106 to return to the power save mode, and then exit the power save mode before the AP 112 begins transmission to the STA 106. Thus, the STA 106 may achieve power savings during the outage time 920.

The STA 106 may learn the expected length of the outage time 920. For example, the STA 106 may learn the expected length of time between sending the service initiation frame 912 and receiving a first data frame 914 from the AP 112, or the expected length of time between receiving the acknowledge frame 918 and receiving the first data frame.

However, the AP 112 may sometimes deviate from the expected length of the outage time 920. In such scenarios, the AP 112 may begin transmission of communications to the STA 106 sooner than the STA 106 had estimated. If such communications are transmitted before the STA 106 exits the power save mode, then the STA 106 may miss the communications.

Thus, to avoid missing communications from the AP 112, the STA 106 may provide, e.g., in the service initiation frame 912, an indication that an outage delay will occur following the acknowledge frame 918. The STA 106 may provide this indication regardless of whether it will reconfigure its receiver. Further, the STA 106 may specify a duration of the outage delay, as discussed with regard to FIG. 9A. For example, the STA 106 may specify that the outage delay will have a duration equal to, shorter than, or otherwise based on, the estimated length of the outage time 920. As another example, the STA 106 may specify that the outage delay will have a duration that is the greater of: (1) the estimated length of the outage time 920, and (2) the minimum time required for the STA 106 to enter and then exit the power saving mode (e.g., at least as long as the time required to power down and power up a transceiver). In other examples, the STA 106 may forego entering the power save mode in response to determining that the minimum time required for the STA 106 to enter and then exit the power saving mode exceeds the estimated length of the outage time 920.

By indicating that an outage delay will occur, the STA 106 may guarantee that the AP 112 will not begin transmission prior to the end of the specified outage delay. Thus, the STA 106 may define a minimum time during which it may safely remain in the power save mode, even if the AP 112 moves the buffered frames to the transmission buffer more quickly than expected.

It should be appreciated that other, similarly predictable outage times may result due to other delays at the AP 112. The STA 106 may similarly learn expected durations of such other outage times, and may use the expected durations to manufacture further power savings opportunities in a manner similar to that shown in FIG. 9C.

Example Embodiments

Some specific examples of the methods disclosed herein may be implemented as follows.

A method may include a wireless communication device changing a configuration of a receiver of the wireless communication device from a first configuration to a second configuration, wherein the receiver is not available to receive communications during changing the configuration; and transmitting, after the changing the configuration, a communication frame including: information identifying the second configuration; and an indication that the receiver is ready to receive communications according to the second configuration.

The preceding method may further include the wireless communication device determining that a communication channel is unavailable for communications by the wireless communication device, wherein the changing the configuration occurs in response to the determining; wherein the transmitting occurs during a scheduled transmit opportunity after the changing the configuration.

The method according to either of the two preceding paragraphs may further include the wireless communication device entering a power-save state, during which the receiver is not available to receive communications, wherein the changing the configuration occurs while the wireless communication device is in the power-save state; and exiting the power-save state after the changing the configuration, wherein the communication frame includes a notification that the wireless communication device has exited the power-save state.

A wireless communication device may include a receiver configured to receive wireless communications from a second wireless communication device; a transmitter configured to transmit wireless communications to the second wireless communication device; a processor communicatively coupled to the receiver and the transmitter, wherein the processor is configured to cause the wireless communication device to: receive, from the second wireless communication device, a first communication frame including: information identifying a first configuration of a receiver of the second wireless communication device; and an indication that the receiver of the second wireless communication device will not be ready to receive communications according to the first configuration until after an outage duration has passed following receipt of an acknowledgement frame responsive to the first communication frame; and in response to the receiving the first communication frame, transmitting the acknowledgement frame responsive to the first communication frame; and delaying further transmissions to the second wireless communication device until after the outage duration has passed.

The processor of the preceding wireless communication device may be further configured to cause the wireless communication device to receive, from the second wireless communication device, a second communication frame including: information identifying a second configuration of the receiver of the second wireless communication device; and an indication that the receiver of the second wireless communication device is ready to receive communications according to the second configuration; and in response to the receiving the second communication frame, transmitting the acknowledgement frame responsive to the second communication frame; and transmitting at least one further transmission to the second wireless communication device without waiting until after the outage duration has passed.

The wireless communication device of either of the two preceding paragraphs, wherein the first communication frame further includes information identifying the length of the outage delay.

A method may include a wireless communication device changing a configuration of a receiver of the wireless communication device from a first configuration to a second configuration while the wireless communication device is in a power-save mode, wherein the receiver is not available to receive communications during the changing the configuration; exiting the power-save mode; transmitting a communication frame indicating that the wireless communication device has exited the power-save mode, wherein the communication frame includes: information identifying the second configuration; and an indication that the receiver of the wireless communication device will not be ready to receive communications according to the first configuration until after an outage delay has passed following receipt of an acknowledgement frame responsive to the communication frame. The method may further include the wireless communication device receiving an acknowledgement frame responsive to the communication frame; entering the power-save mode in response to the receiving the acknowledgement frame; and exiting the power-save mode prior to expiration of the outage delay.

In the method of the preceding paragraph, the communication frame may further include information identifying the length of the outage delay.

In the method of the preceding paragraph, the communication frame may be received by a second wireless communication device, and the acknowledgement frame may be transmitted by the second wireless communication device. The method may further include determining an expected delay duration between the second wireless communication device receiving the communication frame, and the second wireless communication device transmitting data according to the second configuration; and specifying the length of the outage delay based on the expected delay duration.

Embodiments of the present disclosure may be realized in any of various forms. For example some embodiments may be realized as a computer-implemented method, a computer-readable memory medium, or a computer system. Other embodiments may be realized using one or more custom-designed hardware devices such as ASICs. Other embodiments may be realized using one or more programmable hardware elements such as FPGAs.

In some embodiments, a non-transitory computer-readable memory medium may be configured so that it stores program instructions and/or data, where the program instructions, if executed by a computer system, cause the computer system to perform a method, e.g., any of a method embodiments described herein, or, any combination of the method embodiments described herein, or, any subset of any of the method embodiments described herein, or, any combination of such subsets.

In some embodiments, a wireless device may be configured to include a processor (or a set of processors) and a memory medium, where the memory medium stores program instructions, where the processor is configured to read and execute the program instructions from the memory medium, where the program instructions are executable to implement any of the various method embodiments described herein (or, any combination of the method embodiments described herein, or, any subset of any of the method embodiments described herein, or, any combination of such subsets). The device may be realized in any of various forms.

Although the embodiments above have been described in considerable detail, numerous variations and modifications will become apparent to those skilled in the art once the above disclosure is fully appreciated. It is intended that the following claims be interpreted to embrace all such variations and modifications. 

What is claimed is:
 1. A wireless communication device, comprising: a receiver configured to receive wireless communications from a second wireless communication device; a transmitter configured to transmit wireless communications to the second wireless communication device; a processor communicatively coupled to the receiver and the transmitter, wherein the processor is configured to cause the wireless communication device to: configure the receiver according to a first configuration of the receiver; transmit, via the transmitter, after the configuring the receiver according to the first configuration, configuration information specifying a second configuration of the receiver; transmit, via the transmitter, outage delay information specifying a length of time during which the receiver will be unavailable while the wireless communication device configures the receiver according to the second configuration.
 2. The wireless communication device of claim 1, wherein the processor is further configured to cause the wireless communication device to: receive, via the receiver, an acknowledgement frame confirming the configuration information; and configure the receiver according to the second configuration in response to the receiving the acknowledgement frame, wherein the configuring the receiver is completed within a length of time equal to the specified length of time following the receiving the acknowledgment frame.
 3. The wireless communication device of claim 1, wherein the processor is further configured to cause the wireless communication device to: determine the outage delay information based at least in part on the second configuration of the receiver.
 4. The wireless communication device of claim 3, wherein the determining the outage delay information is based on a difference between the first configuration and the second configuration.
 5. The wireless communication device of claim 1, wherein the configuration information and the outage delay information are transmitted in a same frame.
 6. The wireless communication device of claim 1, wherein the outage delay information is transmitted during an association process between the wireless communication device and a second wireless communication device.
 7. The wireless communication device of claim 1, wherein the transmitted configuration information comprises at least one of an indication of a channel width of the receiver and an indication of a number of active receive spatial streams of the receiver.
 8. A method comprising: by a wireless communication device: operating a receiver of the wireless communication device according to a first configuration of the receiver; transmitting configuration information specifying a second configuration of the receiver; transmitting outage delay information specifying a length of time during which the receiver will be unavailable while the wireless communication device configures the receiver according to the second configuration.
 9. The method of claim 8, further comprising: by the wireless communication device: receiving an acknowledgement frame confirming the configuration information; and configuring the receiver according to the second configuration in response to the receiving the acknowledgement frame, wherein the configuring the receiver is completed within a length of time equal to the specified length of time following the receiving the acknowledgment frame.
 10. The method of claim 8, further comprising: by the wireless communication device: determining the outage delay information based at least in part on the second configuration of the receiver.
 11. The method of claim 10, wherein the determining the outage delay information is based on a difference between the first configuration and the second configuration.
 12. The method of claim 8, wherein the configuration information and the outage delay information are transmitted in a same frame.
 13. The method of claim 8, wherein the outage delay information is transmitted during an association process between the wireless communication device and a second wireless communication device.
 14. The method of claim 8, wherein the transmitted configuration information comprises at least one of an indication of a channel width of the receiver and an indication of a number of active receive spatial streams of the receiver.
 15. An apparatus, comprising: a memory storing software instructions; and a processing element communicatively coupled to the memory, the processing element configured to execute the software instructions, wherein, in executing the software instructions, the processing element causes the apparatus to: configure a receiver according to a first configuration; transmit, while the receiver is configured according to the first configuration, configuration information specifying a second configuration of the receiver; transmit, while the receiver is configured according to the first configuration, outage delay information specifying a length of time during which the receiver will be unavailable while the apparatus configures the receiver according to the second configuration.
 16. The apparatus of claim 15, wherein, in executing the software instructions, the processing element further causes the apparatus to: receive an acknowledgement frame confirming the configuration information; and configure the receiver according to the second configuration in response to the receiving the acknowledgement frame, wherein the configuring the receiver is completed within a length of time equal to the specified length of time following the receiving the acknowledgment frame.
 17. The wireless communication device of claim 15, wherein, in executing the software instructions, the processing element further causes the apparatus to: determine the outage delay information based at least in part on the second configuration of the receiver.
 18. The wireless communication device of claim 17, wherein the determining the outage delay information is based on a difference between the first configuration and the second configuration.
 19. The apparatus of claim 15, wherein the configuration information and the outage delay information are transmitted in a same frame.
 20. The apparatus of claim 15, wherein the outage delay information is transmitted during an association process between the wireless communication device and a second wireless communication device. 